| Description | Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS). Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane. Upon initiation of apoptosis, PS loses its asymmetric Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS). Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane. Upon initiation of apoptosis, PS loses its asymmetric distribution across the phospholipid bilayer and is translocated to the extracellular membrane leaflet marking cells as targets of phagocytosis. Once on the outer surface of the membrane, PS can be detected by fluorescently labeled Annexin V in a calcium-dependent manner. In early-stage apoptosis, the plasma membrane excludes viability dyes such as propidium iodide (PI), 7-AAD. These cells will stain with Annexin V but not a viability dye, thus distinguishing cells in early apoptosis. However, in late stage apoptosis, the cell membrane loses integrity thereby allowing Annexin V to also access PS in the interior of the cell. A viability dye can be used to resolve these late-stage apoptotic and necrotic cells (Annexin V, viability dye-positive) from the early-stage apoptotic cells (Annexin V positive, viability dye-negative). This kit is suitable for the identification and enumeration of dead cells, such as apoptotic or necrotic cells, by flow cytometry.A1456542Components20T50T100TStorageQuantity Per TestA1456542A10X Annexin V Binding Buffer5 mL10 mL20 mL2-8℃200 µL per 0.5-1.0x10⁵ cellsA1456542BAnnexin V-PE-Cy7200 µL500 µL1 mL2-8℃. Store in the dark.10 µL per 0.5-1.0x10⁵ cellsA1456542C7-AAD Staining Solution 40 µL 100 µL200 µL2-8℃. Store in the dark.2 µL per 0.5-1.0x10⁵ cellsNote: The recommended number of cells to stain per test is 0.5-1.0x10⁵ cells. Precautions 1. Please try to avoid light when using to slow down the quenching of fluorescence. 2. 7-AAD Solution is toxigenic and mutagenic; handle with care. 3. Due to the calcium dependence of the Annexin V:PS interaction, it is critical to avoid buffers containing EDTA or other calcium chelators during Annexin V experiments. Instruction for use 1. Dilute 10x Binding Buffer to 1x using distilled water (1 mL 10x Binding Buffer + 9 mL ddH2O). 2. Wash cells twice with cold PBS and then resuspend the desired amount of cells in Annexin V Binding Buffer at a concentration of 0.5-1.0x10⁶ cells /mL. 3. Add 10 µL of PE-Cy7 Annexin V and 2 µL 7-AAD to 100 µL of the cell suspension. 4. Add 100 µL of 1x Binding Buffer to each assay. Gently vortex the cells and incubate for 10 min at RT (25°C) in the dark. 5. Analyze by flow cytometry within 1 hr... Read More | B665530 Component 50 T 200 T Storage B665530A Buffer RCL 125 mL 2×260 mL 2-8℃ B665530B Buffer GR 15 mL 50 mL RT B665530C Buffer GL 15 mL 50 mL RT B665530D Buffer GW1 (concentrate) 13 mL 52 mL RT B665530E Buffer GW2 (concentrate) 15 mL 50 mL RT B665530F Buffer GE 15 mL 60 mL RT B665530G B665530 Component 50 T 200 T Storage B665530A Buffer RCL 125 mL 2×260 mL 2-8℃ B665530B Buffer GR 15 mL 50 mL RT B665530C Buffer GL 15 mL 50 mL RT B665530D Buffer GW1 (concentrate) 13 mL 52 mL RT B665530E Buffer GW2 (concentrate) 15 mL 50 mL RT B665530F Buffer GE 15 mL 60 mL RT B665530G Proteinase K 1.25 mL 4×1.25 mL RT B665530H Spin Columns DM with Collection Tubes 50 sets 200 sets RTProduct IntroductionThis reagent kit is suitable for extracting total DNA, including genomic DNA, mitochondrial DNA, and viral DNA, from fresh or frozen whole blood (blood samples treated with anticoagulants such as citrate, EDTA, or heparin), plasma, serum, erythrocyte sedimentation rate brown layer, lymphocytes, cell-free body fluids, and other samples. This product can process 0.1-1 mL of whole blood with a maximum yield of 30% µ g. It can purify DNA with sizes ranging from 100 bp to 50 kb. The purified DNA has high yield and good quality, and can remove protein, pigment, lipid, and other inhibitory impurities to the maximum extent. It can be directly used for PCR, fluorescence quantitative PCR, enzyme digestion, and Southern Blot experiments.Self prepared reagent: anhydrous ethanol.Preparation and important precautions before the experiment:1. The sample should avoid repeated freeze-thaw cycles, otherwise it may result in smaller extracted DNA fragments and a decrease in extraction volume.2. This reagent kit can extract up to 0.1-1 mL of whole blood samples or 1 × 107 white blood cells.3.Before the first use, anhydrous ethanol should be added to Buffer GW1 and Buffer GW2 according to the instructions on the reagent bottle label.4. Before use, please check if there is any crystallization or precipitation in the Buffer GL. If there is any crystallization or precipitation, please incubate the Buffer GL in a 56 ℃ water bath and dissolve it again.5. The Buffer RCL in the reagent kit cannot be used again after being turbid.Operation steps:1. Sample processing: 1a When extracting 200 uL of blood sample, add the sample to the centrifuge tube (provided) and proceed directly to the next step of the experiment. 1b When the blood sample size is less than 200 µ When L, add Buffer GR to make up for 200 µ L. Proceed to the next step of the experiment. 1c When the blood sample size exceeds 200 µ When L is reached, add 1-2 times the volume of Buffer RCL, gently vortex or invert and mix well. Centrifuge at 12000 rpm (~13400 × g) for 1 minute and carefully discard the supernatant. If there is still red in the sediment, repeat the above steps once. Then add 200 to the precipitate µ Shake the buffer GR until thoroughly mixed before proceeding to the next step of the experiment. 1d If the processed blood sample is anticoagulant from poultry, birds, amphibians, or lower level organisms, its red blood cells are nucleated cells, and the blood sample size is 5-20 µ L. Can be added to Buffer GR to make up to 200 µ Follow up experiments will be conducted afterwards. Note: If downstream experiments are sensitive to RNA, 4 can be added µ L RNase A (100mg/mL) solution, shake for 15 seconds, and leave at room temperature for 5 minutes. RNase A reagent kit is not provided. If needed, you can order it separately from our company, item number: CW0601S.2. Add 20 to the above solution µ L Protein K, mix well.3. Add 200 µ Shake with L Buffer GL until thoroughly mixed. Note: Do not pre mix Protein K and Buffer GL.4.Incubate at 4.56 ℃ for 10 minutes, invert and mix several times during this time. Attention: The DNA production has reached its maximum after 10 minutes of incubation, and further extension of incubation time has no effect on DNA production and purity.5. Add 200 µ L anhydrous ethanol, invert and mix several times. Short centrifugation causes the liquid on the tube wall and wall cover to concentrate at the bottom of the tube.6. Add all the solution obtained in step 5 to the spin columns DM that have been loaded into the collection tube. If the solution cannot be added at once, it can be transferred multiple times. Centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube.7. Add 500 to the adsorption column µ L Buffer GW1 (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube. Note: If the extracted sample is the blood genome of species such as mice or monkeys that are difficult to remove heme, it is recommended to repeat step 7.8. Add 500 to the adsorption column µ L Buffer GW2 (check if anhydrous ethanol is added before use), centrifuge at 12000 rpm for 1 minute, discard the waste liquid in the collection tube, and place the adsorption column back into the collection tube. Note: To further improve DNA purity, repeat step 8.9.Centrifuge at 9.12000 rpm for 2 minutes and discard the waste liquid from the collection tube. Place the adsorption column at room temperature for a few minutes to thoroughly air dry. Note: The purpose of this step is to remove residual ethanol from the adsorption column, which can affect subsequent enzymatic reactions (such as enzyme digestion, PCR, etc.)10. Place the adsorption column in a new centrifuge tube (provided by oneself) and add 50-200 to the middle of the adsorption column in the air µ L Buffer GE or sterilized water, leave at room temperature for 2-5 minutes, centrifuge at 12000 rpm for 1 minute, collect DNA solution, and store DNA at -20 ℃. Note: 1) If downstream experiments are sensitive to pH or EDTA, they can be washed off with sterilized water. The pH value of the eluent has a significant impact on the elution efficiency. If water is used as the eluent, its pH value should be ensured to be between 7.0-8.5 (NaOH can be used to adjust the pH value of the water to this range). When the pH value is below 7.0, the elution efficiency is not high. 2) If the final concentration of DNA needs to be increased, the obtained DNA eluent can be added back to the adsorption membrane, left at room temperature for 2-5 minutes, and centrifuged at 12000 rpm for 1 minute. 3) Because DNA stored in water is affected by acidic hydrolysis, if long-term storage is required, it is recommended to elute with Buffer GE and store at -20 ℃... Read More | Live & deadtm animal cell viability / toxicity detection kit (calcein am, ethd-i) is a kit that provides double fluorescent staining for the detection of animal cell death and survival. The two probes in the kit can respectively measure the activity of cellular lactonase and the integrity of Live & deadtm animal cell viability / toxicity detection kit (calcein am, ethd-i) is a kit that provides double fluorescent staining for the detection of animal cell death and survival. The two probes in the kit can respectively measure the activity of cellular lactonase and the integrity of plasma membrane to reflect cell viability. The kit can be used for fluorescence microscopy, flow cytometry, microplate reader and other fluorescence detection systems. This kit can be applied to most eukarYOtic mammalian cells, including some tissues with adherent nuclei, but it is not applicable to fungi and yeast. Compared with trypan blue, the kit is faster, safer and more sensitive.Component： Product parameters：Calcein am: ex/em = 494 / 517 nm; Ethd-i: ex/em = 528 / 617 nm (bound DNA)Usage:Fluorescence microscopy detection1. Prepare working fluidPreparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution: Remove the original solution of Calcein AM and EthD-I and restore them to room temperature. Add 20 µ L 2 mM EthD-I and 5 µ Mix 4 mM Calcein AM with 10 mL PBS or other serum-free buffer or culture medium, vortex well. The above working solution can be directly used for cell staining.Note: The aqueous solution of Calcein AM is easily hydrolyzed and should be used up every day. The concentration selection of Calcein AM and EthD-I varies depending on the type of cell used, with a recommended concentration range of 0.1-10 µ M.2. Prepare cells and conduct experiments(1) For adherent cells, they can be washed 2-3 times with 1 × PBS before staining. For suspended cells, centrifuge at room temperature of 250-1000 × g for 5 minutes and collect cells for staining.(2) Wash the cells thoroughly 2-3 times with 1 × PBS to remove residual esterase activity.(3) For adherent cells, add sufficient amount of Calcein AM/EthD-I staining solution. For suspended cells, add an appropriate amount of staining solution to control the cell density between 1-5 × 105/mL.(4) Incubate at room temperature in dark for 15-20 minutes (if the working solution concentration is high or the incubation temperature is high, the incubation time should be appropriately reduced).(5) Observe the labeled cells under a fluorescence microscope.Flow cytometry detection1. Remove the reagent and restore it to room temperature.2. Preparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution: Take out the original solution of Calcein AM and EthD-I, and restore to room temperature. Add 20 µ L 2 mMEthD-I and 5 µ Vortex mix 4 mM Calcein AM with 10 mL PBS or other serum-free buffer or culture medium. The working fluid can directly stain cells.3. Wash cells thoroughly 2-3 times with 1 × PBS.4. Suspend cells with 0.5 mL of staining solution and control the cell density to 1-5 × 105/mL.Note: It is recommended to prepare two additional cell samples, each containing only one dye (Calcein AM and EthD-I), for compensatory regulation of flow cytometry single staining; Prepare another cell sample containing only buffer solution (which should be consistent with the buffer used to prepare Calcein AM and EthD-I detection working solutions) as a negative control for flow cytometry analysis.5. Incubate at room temperature in dark for 15-20 minutes.6. Within 1-2 hours, cell activity was detected by flow cytometry. Calcein AM can be excited by a 488 nm laser, with fluorescence emission spectra detected at around 530 nm and EthD-I emission spectra at around 610 nm.Note: When using the cell circle gate, attention should be paid to excluding cell debris and using a single staining tube to regulate compensation. Double staining tube flow cytometry should obtain two relatively independent cell populations: a live cell population displaying green fluorescence and a dead cell population displaying red fluorescence.ELISA reader detection1. Cultivate an appropriate amount of adherent or suspended cells in a 96 well black ELISA plate.Note: Dead cells can be obtained by treating cells with 1% saponin or 0.1-0.5% digitalis saponin for 10 minutes.2. Preparation 2 µ M Calcein AM and 4 µ M EthD-I staining solution:Remove the original solutions of Calcein AM and EthD-I and restore them to room temperature. Add 20 µ L 2 mM EthD-I and 5 µ Mix 4 mM Calcein AM 10 mL PBS or other serum-free buffer or culture medium, vortex well.Note: (1) 10 mL of staining solution is sufficient to stain a 96 well plate, and the volume of the staining solution can be adjusted according to experimental needs. The concentrations of Calcein AM and EthD-I can range from 0.1 to 10 µ Explore between M.(2) The aqueous solution of Calcein AM is easily hydrolyzed and should be used up every day. EthD-I working solution can be stored at -20 ℃ for at least one year.3. Wash the cells thoroughly with 1 × PBS to remove residual esterase activity. For adherent cells, add 100 to each well µ Wash cells with PBS. For suspended cells, add 100 µ Resuspend cells with L PBS and centrifuge to remove the supernatant. Repeat the above operation.4. Add 100 to each hole µ L PBS.5. Add 100 to each hole µ L staining solution, making the total volume of each well 200 µ L. The final concentration of Calcein AM is 1 µ M. The final concentration of EthD-I is 2 µ M. Gently shake the culture plate to evenly cover the cells with the liquid.Incubate at room temperature in dark for 30-45 minutes.Note: The optimal incubation time varies for different cells, with 30 minutes as the initial incubation time. Subsequently, the staining time can be adjusted and optimized according to the actual staining effect to obtain a more ideal staining effect.7. Enzyme reader detection. When the ELISA reader is set to fluorescein, it can detect Calcein AM; When the ELISA reader is set to rhodamine or Texas Red, EthD-I can be detected. Select the optimal emission and excitation wavelengths based on spectral characteristics.Note: By comparing the relative fluorescence values (RFU) measured between the sample group and the control group, the changes in the number of dead and live cells can be obtained. Another method of data analysis is also provided below.The following method can calculate the ratio of live cells to dead cells in a certain region. The required samples include dead cell control group, live cell control group, and the sample group to be tested. Dead cells can be obtained by treating cells with 1% saponin or 0.1-0.5% digitalis saponin for 10 minutes.1. Prepare staining solution and follow the above steps to stain cells. Additionally, prepare 1 mL and 2 mL separately µ M Calcein AM and 4 µ M EthD-I solution, stain the control group according to the following instructions. For the following groups of cells or cell-free groups, it is necessary to maintain complete consistency in cell count, detection of working solution concentration, incubation time, and incubation temperature.2. Measurement of sample group and control group:A. The measured values of the sample group at 645 nm are denoted as Calcein AM and EthD-I=F (645) sam.B. The measured values of the sample group at 530 nm are denoted as Calcein AM and EthD-I=F (530) sam.C. The measurement value of dead cell EthD-I single staining control group at 645 nm is denoted as EthD-I=F (645) maxD. The measurement value of dead cell Calcein AM single staining control group at 645 nm is recorded as Calcein AM=F (645) minE. The measurement value of live cell EthD-I single staining control group at 530 nm is recorded as EthD-I=F (530) min.F. The measurement value of live cell Calcein AM single staining control group at 530 nm is denoted as Calcein AM=F (530) max.G. A blank control well without cells (with or without dye), the detection value at 530 nm is recorded as F (530) 0.H. A blank control well without cells (with or without dye), the detection value at 645 nm is recorded as F (645) 0.3. Calculate the ratio of dead cells to live cells based on measurement data:%Live Cells=(B-E) ÷ (F-E)%Dead Cells=(A-D) ÷ (C-D)Determine the ratio of live cells to dead cells in a certain areaBy creating fluorescence spectral standard curves at 530 nm and 645 nm, the number of dead and live cells can be determined, and the fluorescence intensity of each dye is linearly related to the number of dead or live cells in the sample.Matters needing attention：1. please centrifuge the product to the bottom of the tube immediately before use, and then conduct subsequent experiments. 2. phenol red or serum may interfere with the detection of this kit. 3. fluorescent dyes have quenching problems. Please try to avoid light during experimental operation to slow down fluorescence quenching. 4. for your safety and health, please wear experimental clothes and disposable gloves.Scope of application：Dead and live cell staining (animal)... Read More | This reagent kit uses highly sensitive silver dye, which can be applied to protein staining of denatured and non denatured gels. It has the advantages of clear target bands, low background, and flexible control of operation time. In addition, this reagent kit has added a short-term sensitization This reagent kit uses highly sensitive silver dye, which can be applied to protein staining of denatured and non denatured gels. It has the advantages of clear target bands, low background, and flexible control of operation time. In addition, this reagent kit has added a short-term sensitization step, which can significantly reduce the background and enhance the brightness of the target band. P665901Component20 TStorageP665901ASilver Stain Sensitizer (500×)2×1 mLRTP665901BSilver Stain Enhancer3 mLRTP665901CSilver Stain2×250 mLRTP665901DSilver Stain Developer4×125 mLRT Matters needing attention1. Please prepare 50 ml of fixed solution (ultrapure water: ethanol: acetic acid=6:3:1), 50 ml of eluent (10% ethanol), and 50 ml of termination solution (5% acetic acid) in advance.2. Please use deionized water and clean glass or plastic containers during operation, and wear disposable gloves for operation.The entire silver dyeing process needs to be carried out on a shaker, with a rotation speed of about 60 rpm.4. Self prepared ethanol and glacial acetic acid are required.Instructions for useThe dosage of each solution in the following operation steps takes the gel with a size of 8.5 × 5.5 cm and a thickness of 1.0 mm as an example. The gel is immersed in the solution completely, and is operated on a shaker, with a general dosage of 25 ml. For large gel, the dosage of each solution should be scaled up according to the gel volume. Please prepare 50 ml of fixed solution (ultrapure water: ethanol: glacial acetic acid=6:3:1), 50 ml of eluent (10% ethanol), and 50 ml of termination solution (5% glacial acetic acid) in advance.1. Water washing: After electrophoresis is completed, wash the gel twice with ultrapure water for 5 minutes each time.2. Fixation: Fix the gel twice with 25 ml of fixative solution for 15 minutes each time.3. Elution: Wash the adhesive twice with eluent, each time for 5 minutes.4. Water washing: Wash the glue twice with ultrapure water, each time for 5 minutes.5. Sensitization: put the gel washed in the previous step into the silver dye sensitization working solution, incubate it accurately for 1 minute at room temperature, and then wash it with ultrapure water for three times, each time for 20 seconds. Preparation of silver staining sensitization working solution: Take 50 µ l Silver Stain Sensitivity (500 x) and add it to 25 ml of ultrapure water, mix well.6. Silver staining: discard ultrapure water and incubate gel in silver staining working solution for 30 minutes. Preparation of silver staining working solution: Take 25ml Silver Stain and add 50 µ l Silver Stain Enhanced to mix well.7. Water washing: Quickly wash the glue twice with ultrapure water, with each washing accurately controlled for 20 seconds.8. Development: Immerse the washed gel in the developer immediately and incubate it at room temperature for 2-3 minutes until the protein strip is clear. Preparation of developer: Take 25ml Silver Stain Developer and add 30 µ l Silver Stain Enhanced to mix well. Attention: Within 30 seconds of development, protein bands begin to appear and continue to develop for 2-3 minutes. If the protein band appears lighter, the development time can be appropriately extended to 5 minutes or more.9. Termination: After washing the developer on the gel with the termination solution, soak the gel in a new termination solution to react for 10 minutes.Experimental imagesSilver staining results of BSA protein samples after 10% SDS-PAGE gel electrophoresisThe molecular weight of BSA protein is about 66 kD, and the loading amounts from left to right are 50 ng, 10 ng, and 5 ng, respectively... Read More | Cell viability and cytotoxicity assays are usually used for drug screening and compound cytotoxicity testing. The CCK-8 kit uses highly water-soluble tetrazolium salt ( called WST-8 ) to produce water-soluble WST-8 for cell proliferation and cytotoxicity assays. Unlike MTT, WST-8 and WST-8 have no Cell viability and cytotoxicity assays are usually used for drug screening and compound cytotoxicity testing. The CCK-8 kit uses highly water-soluble tetrazolium salt ( called WST-8 ) to produce water-soluble WST-8 for cell proliferation and cytotoxicity assays. Unlike MTT, WST-8 and WST-8 have no cytotoxicity in cell culture medium, so multiple downstream experiments can be performed using the same detection plate. CCK-8 method is a convenient colorimetric method for the determination of cell viability. It does not need the solubilization process and only needs the least steps to provide the results. The CCK-8 method can be used for the determination of 96-well microplates and high-throughput screening of 384-well microplates. Advantage：At present, the commercially available liquid CCK-8 kits generally have defects such as harsh storage conditions ( -4C or -20 ), unstable use in different pH ranges, and easy deterioration ( discoloration or precipitation ). The solid instant CCK-8 kit adopts a new formula and Swiss process, which overcomes these shortcomings of the liquid CCK-8 kit. It can be stored at room temperature for a long time ( > 3 years ), ready to use, stable in a wide pH range, and the experimental results are more reliable. Compared with the liquid CCK-8 kit, the solid-soluble CCK-8 kit has higher sensitivity and the biological response time is shortened by half.Application scope:It can be used for drug screening, cell proliferation assay, cytotoxicity assay, tumor drug sensitivity test and activity detection of biological factors. Operating instructions:This reagent kit can be used for drug screening, cell proliferation assay, cytotoxicity assay, tumor drug sensitivity assay, and activity detection of biological factors.1. Carefully and slowly tear along the gap in the packaging bag;2. Pour all the powder in the bag into a clean container containing 10mL of ultrapure water, shake continuously for 1 minute, and use it when the solid is completely dissolved;3. Unused reagents must be stored at low temperatures below 4 ℃.Equipment required for testing:Enzyme reader 96 well plate with 450-490 nm filter;Carbon dioxide incubator;96 well plate, sterilized transparent plate for cell detection;Multi channel pipette (8 or 12 channels: 10-100 µ l);Blood cell counter or cell counter.Cell viability testing:1. Inoculate cell suspension (100 µ l/well) into a 96 well plate and pre culture the plate in a carbon dioxide incubator for 24 hours (37 ℃, 5% CO2);2. Add 10 µ l of CCK-8 solution to each well (be careful not to generate bubbles in the well as it may affect the reading of OD value);3. Incubate the culture plate in the incubator for 1-4 hours;4. Measure the absorbance at 450 nm using an enzyme-linked immunosorbent assay (ELISA) reader;5. If the OD value is not determined temporarily, 10 µ l of 0.1M HCI solution or 1% w/v SDS solution can be added to each well, and the culture plate can be covered and stored in the dark at room temperature. Within 24 hours of measurement, the absorbance will not change.Cell proliferation toxicity testing:1. Inoculate cell suspension (100 µ l/well) into a 96 well plate and pre culture the plate in an incubator for 24 hours (37 ℃, 5% CO2);2. Add 10ul of different concentrations of the substance to be tested to the culture plate;3. Incubate the culture plate in the incubator for an appropriate period of time (e.g. 6, 12, 24, or 48 hours);4. Add 10 µ l of CCK-8 solution to each well (be careful not to generate bubbles in the well as they may affect the reading of the OD value);5. Incubate the culture plate in the incubator for 1-4 hours;6. Measure the absorbance at 450nm using an enzyme-linked immunosorbent assay (ELISA) reader;7. If the OD value is not determined temporarily, 10 µ l of 0.1M HCI solution or 1% w/v SDS solution can be added to each well, and the culture plate can be covered and stored in the dark at room temperature. Within 24 hours of measurement, the absorbance will not change.Calculation method for cell survival rate/inhibition rate:Cell survival rate=[As Ab)/(Ac Ab)] x 100%Inhibition rate=[(Ac As)/(Ac Ab)] x 100%As: absorbance of experimental wells (including cells, culture medium, CCK-8 solution, and drug solution);Ac: absorbance of control wells (including cells, culture medium, CCK-8 solution, without drugs);Ab: Blank well absorbance (including culture medium and CCK-8 solution, excluding cells and drugs).Points for attention： 1.Unused reagents must be stored at low temperature below 4 °C, and stored in the dark at-20 °C for two years after unpacking, so as to avoid repeated thawing ; 2.The culture time of CCK-8 is generally 1-4 hours, but the naked eye can be taken out to observe the color degree in about 30 minutes. According to the cell type, the conditions need to be explored. The best reaction time of CCK-8 is based on the best time of specific color development.3. It is recommended to do a few holes to explore the number of inoculated cells and the culture time after adding CCK-8 reagent ; 3.The WST-8 in this kit will react with reducing agents ( such as some antioxidants ) to interfere with the detection. Before the cell proliferation-toxicity test, the background OD can be checked to confirm whether there is a reducing agent in the substance to be tested. If the effect of reducing agent needs to be removed, the fresh medium can be replaced before adding CCK-8 ( remove the medium, wash the cells twice with the medium, and then add the new medium ) ; 4.Phenol red in the medium does not affect the experimental results, and the absorbance of phenol red can be eliminated by deducting the absorbance of the background in the blank hole during calculation, so it will not affect the detection. 5.It is recommended to use a multi-channel pipette to reduce the difference between parallel holes. When adding CCK-8 reagent, it is recommended to add it obliquely to the wall of the culture plate, not to insert it under the liquid surface of the medium, which is easy to produce bubbles and interfere with OD determination. 6.If the drug contains metal, it has an effect on the color of CCK-8. The final concentration of 1mM lead chloride, ferric chloride and copper sulfate will inhibit the color reaction of 5 %, 15 % and 90 %, and reduce the sensitivity. If the final concentration is 10mM, the color reaction will be 100 % inhibited ; 7.When using a 96-well plate for detection, if the cell culture time is long, attention should be paid to the evaporation problem. On the one hand, because a circle around the 96-well plate is the easiest to evaporate, the method of discarding the surrounding circle can be adopted, and the same amount of PBS, water or culture medium can be added. On the other hand, the 96-well plate can be placed near the water source in the incubator to alleviate evaporation ; 8.When using standard 96-well plates, the minimum inoculation amount of adherent cells is at least 1,000 cells / well ( 100µl medium ). The sensitivity of detecting white blood cells is relatively low, so it is recommended that the inoculation amount should not be less than 2,500 cells / well ( 100 µl medium ). If you want to use a 24-well plate or a 6-well plate experiment, first calculate the corresponding inoculation amount per well, and add the CCK-8 solution according to 10 % of the total volume of the medium per well ; 9.Cell culture time varies according to the type and number of cells ( per well ), usually the color of white blood cells is weak, requiring a longer culture time ( 4 hours ) and a large number of cells ( ~ 105 cells / well ) ; 10.CCK-8 reagent is very low toxic to cells. The continuous reaction between it and dehydrogenase in living cells makes the color of the solution deepen and the OD value increase. The following methods can terminate the CCK-8 reaction ( 96-well plate ) : a ) After the color reaction, the culture plate was placed in a refrigerator at 4 ° C ; b ) 10µL 0.1MHCL solution was added to each well ; c ) 10 µL 1 % ( w / v ) SDS ( sodium dodecyl sulfate ) solution was added to each well. After the reaction stopped, the OD value should be measured within 24 hours. 11.To determine the specific number of cells, it is recommended to do the standard curve at the same time... Read More |